Thermostat.



E. ALEXANDER.

' THERMOSTAT.

AYPLIOA'MON FILED MAR` 31, 1910.-

Patented July 2, 1912.

u# w.. JV H inventor Witnesses Attorneys unieron stern l. ALEXANDER, 0F LEWISTONN', PENNSYLVANIA.

THERMOSTAT.

Specification of Letters Patent.

Patented July 2, 1912.

Application filed March 31,1910. Serial No. 552,613.

,to ./ZZ whom, "it muy concern:

ile it linown that l, ihininn l). ALEXANDERV a citizen ot .the lhiited States, residing at lieuistou'n, in the county oi' Mitllin and #State ot Pennsylvania, have invented a new and us tul 'l`hermostat of which the follou'ing a s1 ecilication. f

rthis invention relates to 'thermostats of the hind -which employ metals o diiierent coelicients ci' expansion.

The ditliculty with thermostats as here tofore constructed is that they are sluggish thermostat mounted in proximityv to a gas llame, for the purpose of shutting oli the gas in case ot accidental extinction of the thune, might work to a certain extent on account ot therast resulting change in teinperature. l3nt a therniostaft in order to be of 'practical value nuist be able to do more than register the (litter-ence between the temperatur'e of a gas or furnace flame und .the ordinary atmosyihere. ltmust be delicately rcsponsive to the slight-est changes in temperature. lhis is particularly the. case where a thermostat is employed as means of maintaining a uniform temperature in, hn incubator, hospital, residence or the like. lt thermostat is to be of value under the last named conditions it must respond to very slight changes in temperature and must act to an extentsuliicient to restore the temperaluret through sui table controlling mechanism, to its normal condition. Gld forms of thermostats are inadequate for these purposes; 'lhey not only permit Wide variations in temperature before acting, but when they do respond their movements are too slight to be of much use. In the case of an incubator, it it is possible for the temperature to rise or'drop tive or ten degrees before the thern'iostat is influenced, and if the thermostat then moves the valve so slightly that a comparatively long period of time elapses' before the normal temperature is restored, it will be apparent that neither the thermostat nor the incubator are of 'much practical value. ln fact', it may be conservatively stated that incubators under usual conditions are almost Worthless on account of detective thermostats. t

The principal. object of the present invention is tovprovide a thermostat which is deli.

cately responsive to slight changes in telnperature; which has a suiciently large lield ot' movement for practical purposes; and

which is adapted if desired to Asup lement the action of expansive metal, -with t e force of gravity, and the principle oit leverage.

With the foregoing and other objects `in view which will appear as the description proceeds, the invention resides in any form of thermostat which embodies the principles 'i of invention exemplified in the accompanying drawing and following specification, and included within the scope of the a pended claims, it bein Vunderstood thatt e preciseembodiment o' invention herein disclosed is merely one example of the invention and that the same may be embodied in many other Ways Within the scope of the claims.

In the accompanying drawings forming part of this specification :MFigure 1 is a side elevation of a thermostat constructed in accordance with the invention. Fig. 2 is a perspective View thereof. Fig. 3 is a sectional view through the left hand end of Fig. 1. Fig. l is a perspective view of the same end.

Like reference numerals` indicate corresponding parts in the different. figures of the drawing. v y

The embodiment of invention herein d-isclosed comprises a suit-able frame made up of the brackets land 2 connected with each other in any desired manner .such as by means of the bar or member 3. f

The numeral 4 indicates a strip of meta of a high-coetlicient of expansion,-Which Will be referred to herein as an expander. 'lhc expander t .is connected withv or .1anchored on the bracket l by means such .as the bolt 5 and nut 6. The oppositetend of the expander 4:, is free and lrests lightly` upon the bottom of the s 'uarehead 7 of the4 bracket 2. Riveted or ot erwise secured to the free end of the expander 4: as indicated los at S, is a strip 9 formedof lmetal'of a. low' i coetlicient of expansion, which will vbe referred to herein as a connector orciunulator. The connector V9 extends in zig-zag relation to the expander 4 and preferably lies above the -same and almost-inl parallelism therewith as shown. The connector 9 preferably isprovided with upstanding side flanges 10--10,"so as to be l"channel shaped i'n 'crosssectiom the flanges 1 0-10 serving to stiifen the connector.' At-its upper end, above the anchored end of the expander 4, the connector 9 'is connected in any suitable manner with the lower end of another ex- 1.0 pander 11, the connected ends of the connector 9 and the-expander 11 being slidably supported in any suitable manner by means i such as the traveler hook 12 having the elongated parallel portions 13-13 which em- 15 brace opposite sides ofa pin 14 set into the head 15 of ther bracket 1. I

vtions 13- 13and pin 14 permit` sli ing movement/fof themembers 9- 11 and'prevent up and down movements thereof. lAt its upper end theexpander 11 is riveted or otherwise secured Aat 16V to an oppositely extending connector" 17 having stiifening -flanges 18. The connected ends of the expander 11Y and. connector 17 are Ymovably supported in any suitable manner such as by means of the hanger. or hook 19 which is engaged at its lower end with a transverse pin 20 mounted in the flanges 18V of the connector 157 and at its upper end, is engaged-with afpn 21 fixed in the head 7 of the'bracket2. VVVThe upper end of the connector. or cumulator 17- is xed to the free end4 of an expander 22 which` is an- 'chored on the head 7 in any suitable man- 85 ner such as by means Vofthe screws 2li- 23. The anchored end of the expander 22 may befformed if desired with an upstanding flange 24. The means for connecting the ends of the connector or cumulator 17 and 40 expander 22 may consist of the/rivets 25 which also serve to secure in position an arm 26 to which is secured a rod 27 or other means forutilizing the action of the thermostat for performing useful operations such, by way of example, as the operation controlling an incubator valve or the Constructed asf described, the operation of the device is substantially as follows: Upon arise in temperature, the expandcrs 2 and 11 expand to the left in Fig. 1. The connector 9 cumulates this expansion so that the upper endof the expander 11 moves the lower end of the connector 17 a distance 56 equal to the sum of the expansion of the two expanders 4 and 11.- At the same time, theV upper expander 22 is expanding in the opposite direction,' with the result that thel arm 26 and rod 27 are moved to a markedI 60 degree. This downward movement. of theI act-iveend of the expander 22' is accelerated' by the torceof gravity anda strong leverage action. The anchored end of expander 22, which will now be apparent is 'not only an expander but also a transformer for pansiori, acts as a fulcrum of a lever. Moreover, as thelower end of the connector 17 disposed-close under the anchored end of the expander 22, the slightest` movement of the lower-end of the connector 417 to the left causes an enormously multiplied downward movement .'ofthe end 'ofthe combined expander and transformer 22,' which movement is accelerated by gravityv action. If the proportions ofthe parts-are arranged approximately as shown in the drawing, movement on the lower endofthe connector 17 is multiplied approximately 24: times at the free end of the transformer22. In addition to the action of the expanders 4 and 11` acting to the left, theexpander 22 acting to the right, increasesv the resulting movementr y i ,l

fIt is foundin practice that a thermostat constructed in accordance with the principles of this invention reacts tb a variation ofone-quarter of a degree Fahrenheit. In other words an incubator or other device or room or building, equipped with the thermostat means-of the present invention can bemaintained constantly at a temperature which will not vary more than a quarter of a degree Fahrenheit above or below normal. In'the case'of an incubator, the economy wvhiclri's =-e1ected,;not only by pne- .venting destruction of" the fertilizing propertics of the eggs by' violent fluctuations 1n temperature, but also by regulating the quantity of oil or other fuel necessary for heating the incubator, renders the thermostat of the present invention anextremely valuable adjunct to inubators. a

An Vanalysis of the device as illustrated.-

in the drawing, shows that each pair of expanda-.rs and connectors, such, for example, as 22 and 17 form in etfect an open base triangle, the expander forming one long side ot' the triangle, the connectorl the other, and the space between the separated ends thereof forining'the open base. The action.

of the members 22 and 17 is practically the same ,as that' of an elongated triangular structure )ivoted at one of its basal cox-ners, so that relative movement of theother corner causes a greatly multiplied movement of the elongated' end or apex of the tri.- anglc. ln addition to the open base triunglc formed by the members 22 and 17, another triangle is formed by the members 17and -11, the second triangle having its apex extending in an opposite direction to that of the first. mentioned triangle; and so on, throughout the alternate and zig-zag arrangement of expandcrs and bonner-,tors or cumulators.

It is found in practice that very little, it any friction is produced on the hanger l2 roanne? and pin 1121-. On the contrary the hanger seems to be balanced by the other parts of the thermostat and vibrates slightly like a balanced scale beam on the lpin 14.

lhe thermostat of the presentinvention xcures practically all the effects of metallic expansion and converts them into useful and multiplied action. rhere is no lost n1otion or stress and strain'of metal as is the :ase where the metals of high and low coefiicients of expansion are secured together' throughout all or the greater part of 'their length; instead, of heilig secured merely at their ends and tree throughout the remainder 'of their lengths as in the present invention.v

By reacting to a change of one quarter degree Fahrenheit and by moving its transformer to a greatly multiplied extent so to perform useful operations, the thermostat of the present invention constitutes an important advance in thermal arts and de vices, and practically overcomes the defects and objections heretofore interfering with the proper operation and commercial value of incubatore. l

What is claimed is: Y

1.. A thermostat having a plurality ot expanders one expander being anchored at one end and the other at its opposite end, connecting mea-ns secured at one end to the free end of one expander and at the other end to the free end of the other expander, the 'free end ot each expander being near the anchored end of the other expander, and means operated ,by said expanders for exerting therniostatic power.

A thermostat having a pluralityT o'tl expanders, one anchored at one end and the other anchored at the other end, a connector secured at one end to -ono expander and at the other end tothe other expander7 said expanders and connector being arranged in zig-zag relation to each other, and means connected with the free end of one expander tor yexerting therniostatic power.

3. A. thermostat having a plurality ot expanders substantially parallel land abreast of each other, one or said expanders being anchored at one end and. the other of said expanders being anchored at the other end` the 'free end ot each expander being disposed opposite the anchored end of the other expander, a diagonally extending connector rigidly secured to one end of one expander and connected at its other end. with the freeV end ot the other expander, and means connected with said expanders for exerting thermostatic power.

fh A thermostat having a plurality of ex-Q panders, one ot' the expanders being an-l chored at one end and the other of said expander-s being anchored at the other end, each expander having a free end disposed adjacent the anchored end,` of the other expander, a plurality of diagonally extending connecting means located between said expanders and connected with the free ends thereof, and means operated by said expand ers orexert-ing thermostatic power.

5. A thermostat having a transformer ronsisting oi .a fiexihle metal strip constitutingl an expander, each strip being anchored at one end. the other end ot said strip being adapted to tall by gravity, a second strip secured to the tree end oit said tirs-t mentioned strip and arranged in approxinnltely V-shaped relation thereto, the end ot said second strip adjacent the anchored end ot the first strip being tree Ytrom said first strip,

an expander independent ot the first inentioned expander for moving the loner end of said last mentioned strip, and means operated by the expanders for transmitting power.

(3. A thermostat having a pair of oppositely extending expanders, one of the ex; panders being anchored at one end and the other of said expander-s being anchored at the opposite end, the tree end ot' each cx ponder being .located adjacent the anchored end oi the other expander, a connector secured at one end to the one expander and at the other end to the other expander, said connector and exp-anders being arranged to form two oppositely extending open-base triangles, and means connected with said expanders for exerting therinostatic power.

7. A thermostat having a plurality ot metals ot' high and low coefiicionts oit expansion, the metals ot high coeflicients being ar ranged alternately with those ot' low cocili cients'Qthe metal at one end ot' the series ol. metals being anchored at one end and the metal. ai the other end ot, said series being.

anchored at the other end, the 'tree end of one end metal being connected with the free. end of the other end metal by means of the interveningmetals being placed in zig-zag relation, and means operated by said metals `for exerting thermostatic power.

S. A thermostatcomprising a seriesot inetallic strips ot different coeliicienls oiq en pansion, each strip being connected al one` end to the strip on one side thereof, and at its opposite end to the strip on the other side thereof, whereby to produce a plurality of oppositely extending il-shaped structures, the strip at one end of said series being anchored at one end and the strip at the other end ot' said series being anchored at the opA posite end, and means operated by-said strips for exerting ,thernuistatic' power.

9. A thermostat having cumnlating means consisting of a plurality of expandcrs a ranged substantially abreast of each other one oi said expanders being anchored atxine end and the other of said expanders being,

anchored at the opposite end, 'the free end of one expander being disposed oppositethe an chored end of the other expander, an intermediate expander, a plurality of strips of metalv of a low coefficient of expansion, each of said strips connecting the free end of, one of said anchored expanders with the opposite end of sald intermediate expander, and

means operated by said expanders for exertingyhthermostatic power.

i each other, and an intermediate non-exponder attached at one end to one end ot oneexpander and at its otherv end to the opppsite end of the other expander, said nongiipander being free 'from the expander# except at its ends and said expanders being free from each other excgpt through the connection of said non-exritaider,. whereby the longitudinal expansion ot said expanders is cmnulated, and power transniission means operated by said oxpanders.

ll. A thermostat comprising an upper expauder anchored at one end, a lower expander anchored atthe other end, an intermediate expander, a connector secured at one end to the free end ofl the upper expander and at the other end to one end of the intermediate expander, and a second connector secured at one end to the intermediate expander and at the other end to the lower expander and means operated by said expanders for exerting thermostatic power.

12. A thermostat comprising a frame, an upper expander secured at oneend to'the frame, a lower expander seem-ed at. the other end to the frame, an intermediate expander, an upper connector secured at one end to the upper expander and at the opposite end to the intermediate expandennnd a lower connector secured at one. cud to the lower expander and at the other end to the intermediate expander, the point of connection between the upper expander and the upper connector bein used as a transformer and means operated by said expanders for exerting thermostatic power.

13. A thermostat comprising an upper cxpander anchored at one end, a lower cxpandcr anchored at the other end, an intermediate expander, a lower connector secured' at oneend to the free end of said lower expander-and at the other end to the intermediate expander, an upper connector secured at one end to the upper expander vand at the metal of a high coetiicient of expansion, said upper expander being secured at one end to said frame, a lower expander formed of a thinl strip of metal of a high coefficient of cxpz'insion, a connector formed of .a metal of a low coetlicient. of expansion secured to one end ot' said lower expander and at the other end to said intermediate expander, anupper connector formed of a strip of'metal of a low coetiicient of expansion secured at one' end to said upper expander and at the other end to said intermediate expander, and

means operated by said expanders for exerting therinostaticpower.

15. A thermostat comprising a pair of Siiv bradlcets spaced apart and rigidly connected t with each other, a iower expander anchored on one of said brackets resting loosely at its opposite end on the other of said brackets, an upper expander Vsecured at one end to said other bracket and projecting at its free end above said irst mentioned bracket, means on the free end of the upper expander for operating c valve, an intermedi :tte 'zpander,v a lower connector secured at its lower end, tothe free end of said lower expander und at its opposite end to said intermediate expander,`an upper connector sev cured at its lower end to said intermediate expander and at its up end of said upper ex an` er, sliding supports for both ends of sai intermediate ex under, means for transmitting power from t 1c connected ends of said u per expander and said. upperv connector, an means for st itening said connectors.

In testimony that l claim the foregoing as r end tothe free :leeg

my own, I have hereto attxed my signature ELMER I. ALE XXS DE in thc presence of two witnesses. 

